Only a fraction of new HIV infections occur within identifiable stable discordant couples in sub-Saharan Africa

Incidence of HIV disclosure among HIV affected heterosexual partners using a community health worker led mechanism in rural Uganda; a quasi-experimental study

BACKGROUND

HIV disclosure is vital in HIV management. Community Health Workers (CHW) were reported to support partner disclosure among HIV affected heterosexual partners with disclosure difficulties. However, time to disclosure attributed to use of CHW led disclosure support mechanism was not documented. This study compared the incidence of sexual partner disclosure among adults living with HIV (ALHIV) with CHW support and those without in the greater Luwero region, Uganda.

METHODS

We conducted a quasi-experimental study with two arms allocated by geographically determined clusters and adjusted for between-group differences; among ALHIV in the greater Luwero region of Uganda who had never disclosed to their current primary sexual partners. We allocated study clusters to either a CHW-led intervention or control arm. In both arms, we consecutively recruited participants; those in the intervention arm received CHW disclosure support in addition to routine care. The overall follow-up was six months, and the primary outcome was disclosure to the partner. We used survival analysis with proportional hazard ratios to determine the time to partner disclosure in both arms.

RESULTS

A total of 245 participants were enrolled, and 230 (93.9%) completed the study; of these, 112 (48.7%) were in the intervention and 118 (51.3%) in the control arm. The mean age was 31 ± 8 years with a range of 18 to 55 years; the majority were females, 176 (76.5%). The cumulative incidence of disclosure was higher in the intervention arm, 8.76 [95% CI: 7.20-10.67] per 1,000 person-days versus 5.15 [95%CI: 4.85-6.48] per 1,000 person-days in the control arm, log-rank test, X2 = 12.93, P < 0.001. Male gender, aHR = 1.82, tertiary education, aHR = 1.51, and relationship duration of > six months, aHR = 1.19 predicted disclosure. Prior disclosure to a relative, aHR = 0.55, and having more than one sexual partner in the past three months, aHR = 0.74, predicted non-disclosure.

CONCLUSION

CHW-led support mechanism increased the rate of sexual partner disclosure among ALHIV with disclosure difficulties. Therefore, to achieve the global targets of ending HIV, near location CHW-led disclosure support mechanism may be used to hasten HIV disclosure in rural settings.

Experiences and challenges of using community health worker-led mechanism in supporting HIV disclosure among adults living with HIV in heterosexual relationships in the rural Uganda

BACKGROUND

HIV status disclosure among sexual partners is vital in HIV management. Community health workers (CHW) support HIV disclosure among adults living with HIV (ALHIV) in sexual relationships with disclosure difficulties. However, experiences and challenges of using CHW-led disclosure support mechanism were not documented. This study explored experiences and challenges involved in using CHW-led disclosure support mechanism among ALHIV in heterosexual relationships in the rural Uganda.

METHODS

This was a phenomenological qualitative study involving in-depth interviews among CHWs and ALHIV with HIV disclosure difficulties to sexual partners in greater Luwero region, Uganda. We conducted 27 interviews among purposively selected CHWs and participants who had participated in the CHW-led disclosure support mechanism. Interviews were conducted until saturation was reached; and analysis was done using inductive and deductive content analysis in Atlas.

RESULTS

All respondents viewed HIV disclosure as an important strategy in HIV management. Provision of adequate counseling and support to those intending to disclose was instrumental for successful disclosure. However, fear of the negative disclosure outcomes was viewed as a barrier to disclosure. The CHWs were viewed as having an added advantage in supporting disclosure as opposed to the routine disclosure counseling. However, HIV disclosure using CHW-led support mechanism would be limited by possible bleach of client's confidentiality. Therefore, respondents thought that appropriate selection of CHWs would improve their trust in the community. Additionally, providing CHWs with adequate training and facilitation during the disclosure support mechanism was viewed to improve their work.

CONCLUSION

Community health workers were viewed as being more supportive in HIV disclosure among ALHIV with disclosure difficulties to sexual partners compared to routine facility based disclosure counseling. Therefore, near location CHW-led disclosure mechanism was acceptable and useful in supporting HIV disclosure among HIV-affected sexual partners in rural settings.

Community Health Workers Improve HIV Disclosure Among HIV-Affected Sexual Partners in Rural Uganda: A Quasi-Experimental Study

BACKGROUND

We evaluated the efficacy of a community health worker (CHW)-led intervention in supporting disclosure among adults living with HIV in heterosexual relationships.

METHODS

We conducted a quasi-experimental study with 2 arms allocated by geographically determined clusters and adjusted for between-group differences among adults living with HIV in the greater Luwero region of Uganda who had never disclosed their status to their current primary sexual partners. Clusters were allocated to either a CHW-led intervention or a control arm. In both arms, participants were consecutively recruited. As opposed to receiving routine care for the control arm, participants in the intervention arm received additional CHW disclosure support. The overall follow-up was 6 months, and the primary outcome was disclosure to the sexual partner. Data were analyzed using a clustered modified Poisson regression model with robust standard errors to determine independent factors associated with disclosure.

RESULTS

Of the 245 participants who enrolled, 230 (93.9%) completed the study, and 112 (48.7%) of those were in the intervention arm. The median age was 30 (interquartile range=25-37) years, the majority were women (76.5%), and most (80%) did not know their partners' HIV status at study entry. At the end of follow-up, the overall disclosure prevalence was 74.4% (95% confidence interval [CI]=68.2, 79.9) and participants in the intervention arm were 51% more likely to disclose compared to those in the control (adjusted relative ratio [aRR]=1.51; 95% CI=1.28, 1.77). Men were 24% (aRR=1.24; 95% CI=1.07, 1.44) more likely to disclose compared to women, and membership in an HIV/AIDS association increased disclosure by 18% (aRR=1.18; 95% CI=1.01, 1.39).

CONCLUSION

CHW support improved disclosure among adults living with HIV in heterosexual relationships when compared to routine care. Therefore, CHW-led mechanisms may be utilized in increasing disclosure among adults living with HIV in heterosexual relationships in rural settings.

Effect and implementation experience of intensive adherence counseling in a public HIV care center in Uganda: a mixed-methods study

Background

Intensive adherence counseling (IAC) is an intervention recommended by the World Health Organization to improve anti-retroviral therapy (ART) adherence among people living with HIV on ART with unsuppressed viral load; and in 2016, the intervention was implemented in Uganda. This study evaluated the effect and experiences of providing IAC in an urban HIV care center in Kampala, Uganda.

Methods

This was a sequential explanatory mixed-method study that compared viral load suppression during IAC implementation (intervention) to the period before IAC at Kisenyi Health centre IV. Data were abstracted from patient files and viral load register. The effect of IAC on viral load suppression and associated factors were analyzed using modified Poisson regression with robust standard errors. Using in-depth interviews and an inductive analysis approach in Atlas-ti 8. We also explored experiences of providing IAC among healthcare workers.

Results

A total of 500 records were sampled: 249 (49.8%) in the intervention period and 251 (51.2%) in the pre-intervention period. The mean age was lower during the intervention period 33.1 (± 12.0) than 36.5 (± 13.4) in the pre- intervention period, p = 0.002. More clients were currently on Protease-based regimen in the pre-intervention period 179 (71.3%) than 135 (54.2%) in the intervention period, p ≤ 0.001. In the intervention period, all eligible clients received IAC [249/249 (100.0%)]. Overall, 325 (65.0%) received IAC and of these, 143 (44.1%) achieved viral load suppression compared to 46 (26.3%) who received regular counseling. Receiving IAC significantly increased viral load suppression by 22% (aPR 1.22, 95% CI 1.01–1.47). Clients on Protease-based regimen were less likely to suppress than those on Efavirenz or Nevirapine-based regimens (aPR 0.11, 95% CI 0.08–0.15). All the interviewed healthcare workers lauded IAC for improving ART adherence. However, patient and health care system related factors hindered adherence during IAC.

Conclusions

The full potential of IAC in achieving viral load suppression in this setting has not been reached due to a combination of the patient and health care system related factors. Provision of adequate IAC necessities and use of patient centered approach should be emphasized to obtain the maximum benefit of the intervention.

Assessment of an HIV-prevention intervention for couples in peri-urban Uganda: pervasive challenges to relationship quality also challenge intervention effectiveness

Reducing multiple and concurrent partnerships has been identified as a priority in generalised HIV epidemics, yet developing successful interventions to bring about such behaviour change has proven challenging. We offered a three-session intervention aimed to improve couple relationship quality and address HIV risk factors, particularly concurrent sexual partnerships (CSP), in a peri-urban community of Kampala, Uganda. Before launching the intervention, a different group of community members participated in eight single-gender focus group discussions (FGDs) which explored issues of couple relationship quality and satisfaction. Findings from the FGDs guided the intervention. All 162 couples invited to the intervention completed a survey pre- and post-intervention. In FGDs, women and men discussed challenges faced in their relationships, including pervasive dissatisfaction, financial constraints, deception and lack of trust, poor communication, lack of sexual satisfaction, and concurrent sexual partnerships. A difference-in-difference analysis showed no measurable impact of the intervention on relationship quality or sexual risk behaviours over a six-month follow-up among 183 individuals who participated in the intervention, although many stated in response to open-ended questions that they had experienced positive relationship changes. Qualitative findings suggest high demand for couple-focused interventions but also reveal many individual-, couple-, community- and structural-level factors which contribute to women and men seeking concurrent sexual partnerships. More intensive interventions may be needed to overcome these barriers to behaviour change and reduce HIV risk. These findings also raise questions about how to interpret divergent qualitative and quantitative data, a topic which has received little attention in the literature.

Community perceptions and personal accounts of HIV discordance in rural western Kenya

Among HIV-discordant couples, the literature is sparse regarding issues related to stigma, relationships and coping. Objectives were to explore: 1) perceptions about discordant HIV status; 2) understanding of HIV discordancy; 3) effects of discordancy on couples; and 4) adaptation and coping strategies for discordant HIV status. A survey was administered to 202 members of heterosexual discordant couples in rural western Kenya. In addition, to understand the community perspective, in-depth interviews (IDI) (n = 26) and focus group discussions (FGD) (n = 10) were conducted with community opinion leaders, healthcare workers and members of discordant couples. More than 70% of men (73.4%) and women (80.4%) surveyed agreed that their relationship changed for the worse when they disclosed their HIV status to their partner. Participants of IDIs and FGDs provided several explanations for discordancy including the perception that discordancy is a lie, the negative partner has "thick blood", HIV infection is a punishment for sexual promiscuity or cultural disobedience, and that HIV is a punishment from God. Members of discordant couples reported experiencing tension and fear, stigma and rejection, and changes in partner support. Adaptation and coping strategies included counselling, sero-sorting and pursuing concordancy with the uninfected partner. HIV discordancy in a relationship can potentially cause long-term negative emotional and physical consequences. There is an acute need to develop and disseminate locally sensitive HIV-discordant couple counselling messages, and to provide couple-centred HIV care and treatment. Communication can help couples rebuild and rebalance their relationship and adjust to a new normal.

Discordance, Disclosure and Normative Gender Roles: Barriers to Couple Testing Within a Community-Level HIV Self-Testing Intervention in Urban Blantyre, Malawi

A community-based HIV self-testing study in Blantyre, Malawi demonstrated that not all individuals living in couples tested with their partner. We describe factors dissuading individuals in couples from self-testing with their partner. Data were drawn from qualitative study exploring consequences of HIV self-testing within couples. In-depth interviews were conducted with 33 individuals living in couples who tested alone. Participants expressed fear of dealing with HIV-discordant relationships. Failure to self-test with a partner was correlated with gender, with more men than women overtly declining or unconsciously unable to have joint HIV self-test. Men feared exposure of infidelity and were often not available at home for economic reasons. Barriers to uptake of couple HIV self-testing seemed to be shaped by gendered dichotomies of social-relationships. To help achieve the first 90% of the UNAIDS 90:90:90 goals, it is important to overcome structural barriers to realise the full potential of HIV self-testing.

Temporal evolution of HIV sero-discordancy patterns among stable couples in sub-Saharan Africa

INTRODUCTION

Objective was to examine the temporal variation of HIV sero-discordancy in select representative countries (Kenya, Lesotho, Mali, Niger, Tanzania, and Zimbabwe) in sub-Saharan Africa at different HIV epidemic scales. A sero-discordant couple is defined as a stable couple (SC) in which one partner is HIV-positive while the other is HIV-negative.

METHODS

A deterministic compartmental mathematical model was constructed to describe HIV transmission dynamics. The model was pair-based, that is explicitly modeling formation of SCs and infection dynamics in both SCs and in single individuals. The model accommodated for different forms of infection statuses in SCs. Using population-based nationally-representative epidemiologic and demographic input data, historical (1980-2014) and future (2015-2030) trends of sero-discordancy and other demographic and epidemiologic indicators were projected throughout HIV epidemic phases.

RESULTS

As the epidemics emerged, about 90% of SCs affected by HIV were sero-discordant. This proportion declined to 45%-88% at epidemic peak and stabilized as the epidemics started their natural decline. The largest reductions in sero-discordancy were in high HIV-prevalence countries. As the epidemics further declined with antiretroviral therapy (ART) scale-up, the proportion of sero-discordant couples among HIV-affected couples was projected to increase to 70%-92% by 2030. The proportion of sero-discordant couples among all SCs increased as the epidemics emerged and evolved, then peaked at 2%-20% as the epidemics peaked, and then declined as the epidemics declined to reach 0.3%-16% by 2030.

CONCLUSIONS

Sero-discordancy patterns varied with the evolution of the epidemics, and were affected by both epidemic phase and scale. The largest variations were found in high HIV-prevalence countries. The fraction of stable couples that are sero-discordant, as opposed to being sero-concordant positive, was projected to increase with ART scale-up and further HIV incidence decline over the coming two decades. These findings inform strategic planning and resource allocation for interventions among sero-discordant couples.

Treatment of HIV for the Prevention of Transmission in Discordant Couples and at the Population Level

The scientific breakthrough proving that antiretroviral therapy (ART) can halt heterosexual HIV transmission came in the form of a landmark clinical trial conducted among serodiscordant couples. Study findings immediately informed global recommendations for the use of treatment as prevention in serodiscordant couples. The extent to which these findings are generalizable to other key populations or to groups exposed to HIV through nonsexual transmission routes (i.e., anal intercourse or unsafe injection of drugs) has since driven a large body of research. This review explores the history of HIV research in serodiscordant couples, the implications for management of couples, subsequent research on treatment as prevention in other key populations, and challenges in community implementation of these strategies.

Differences in knowledge, attitudes and behaviors of Israeli HIV-uninfected gay men in HIV-discordant vs. concordant steady relationships

HIV-discordant gay male couples may play an important role in HIV-transmissions. This cross-sectional study compared the knowledge, attitudes and sexual behaviors of HIV-uninfected gay men, between those in HIV-discordant and those in HIV-concordant steady relationships. Anonymous questionnaires were distributed electronically in designated gay-related internet sites and in AIDS-clinics in 2015. The dependent variable was defined as a steady relationship of an HIV-uninfected man with an HIV-infected partner. Risky sexual behavior was defined as unprotected anal intercourse (UAI) with a sex partner whose HIV-status was either positive or unknown. Of 2,319 responders, 460 (20%) were HIV-uninfected gay men in steady relationships, of whom 72 were in HIV-discordant relationships and 388 were in HIV-concordant relationships. Those in HIV-discordant relationships presented better established knowledge regarding HIV-transmission, more lenient attitudes regarding UAI, and reported being involved in riskier sexual behavior, both within and outside their steady relationship compared to men in HIV-concordant relationships. UAI was performed by 48% of the HIV-discordant couples and was associated with the use of sero-positioning strategy and with achieving undetectable viral-load. These findings reflect the complexity of constant use of condoms during long-term sero-discordant relationships. Targeted interventions for HIV-prevention in HIV-discordant couples should be employed for balancing the partners' desire for intimacy and sexual pleasure in the relationship, while reducing the risk for acquiring HIV.

ABBREVIATIONS

ART: Antiretroviral therapy; PEP: Post exposure prophylaxis; PrEP: Pre exposure prophylaxis; STI: Sexually transmitted infections; UAI: Unprotected anal intercourse.

PrEP implementation research in Africa: what is new?

INTRODUCTION

Of the two million new HIV infections in adults in 2014, 70% occurred in sub-Saharan Africa. Several African countries have already approved guidelines for pre-exposure prophylaxis (PrEP) for individuals at substantial risk of HIV as part of combination HIV prevention but key questions remain about how to identify and deliver PrEP to those at greatest need. Throughout the continent, individuals in sero-discordant relationships, and members of key populations (sex workers, men who have sex with men (MSM), transgender women and injection drug users) are likely to benefit from the availability of PrEP. In addition, adolescent girls and young women (AGYW) are at substantial risk in some parts of the continent. It has been estimated that at least three million individuals in Africa are likely to be eligible for PrEP according to WHO's criteria. Tens of demonstration projects are planned or underway across the continent among a range of countries, populations and delivery settings.

DISCUSSION

In each of the target populations, there are overarching issues related to (i) creating demand for PrEP, (ii) addressing supply-side issues and (iii) providing appropriate and tailored adherence support. Critical for creating demand for PrEP is the normalization of HIV prevention. Community-level interventions which engage opinion leaders as well as empowerment interventions for those at highest risk will be key. Critical to supply of PrEP is that services are accessible for all, including for stigmatized populations. Establishing accessible integrated services provides the opportunity to address other public health priorities including the unmet need for HIV testing, contraception and sexually transmitted infections treatment. National policies need to include minimum standards for training and quality assurance for PrEP implementation and to address supply chain issues. Adherence support needs to recognize that social and structural factors are likely to have an important influence. Combining interventions that build self-efficacy, empowerment and social cohesion, with evidence-based individualized adherence support for PrEP, are most likely to be effective.

CONCLUSIONS

Efficacy of tenfovir-based PrEP is proven but many issues related to implementation remain unclear. Here, we have summarized some of the important implementation questions that need to be assessed as PrEP is rolled out across Africa.

Geographical Patterns of HIV Sero-Discordancy in High HIV Prevalence Countries in Sub-Saharan Africa

INTRODUCTION

Variation in the proportion of individuals living in a stable HIV sero-discordant partnership (SDP), and the potential drivers of such variability across sub Saharan Africa (SSA), are still not well-understood. This study aimed to examine the spatial clustering of HIV sero-discordancy, and the impact of local variation in HIV prevalence on patterns of sero-discordancy in high HIV prevalence countries in SSA.

METHODS

We described the spatial patterns of sero-discordancy among stable couples by analyzing Demographic and Health Survey data from Cameroon, Kenya, Lesotho, Tanzania, Malawi, Zambia, and Zimbabwe. We identified spatial clusters of SDPs in each country through a Kulldorff spatial scan statistics analysis. After a geographical cluster was identified, epidemiologic measures of sero-discordancy were calculated and analyzed.

RESULTS

Spatial clusters with significantly high numbers of SDPs were identified and characterized in Kenya, Malawi, and Tanzania, and they largely overlapped with the clusters with high HIV prevalence. There was a positive correlation between HIV prevalence and the proportion of SDPs among all stable couples across within and outside clusters. Conversely, there was a negative, but weak and not significant, correlation between HIV prevalence and the proportion of SDPs among all stable couples with at least one HIV-infected individual in the partnership.

DISCUSSION

There does not appear to be distinct spatial patterns for HIV sero-discordancy that are independent of HIV prevalence patterns. The variation of the sero-discordancy measures with HIV prevalence across clusters and outside clusters demonstrated similar patterns to those observed at the national level. The spatial variable does not appear to be a fundamental nor independent determinant of the observed patterns of sero-discordancy in high HIV prevalence countries in SSA.

Culture, myths and panic: Three decades and beyond with an HIV/AIDS epidemic in Zimbabwe

Zimbabwe is going through a generalised acquired immunodeficiency syndrome (AIDS) epidemic. The first five years of the epidemic (1985-1990) were characterised by lack of medicines against human immunodeficiency virus (HIV), and an exponential increase in prevalence (65-fold) and incidence (13-fold), which were fuelled by high-risk sexual behaviour. The high HIV prevalence, mortality and stigma yielded great fear and panic in the population, which are thought to have led to confusion and hopelessness, and, in turn, increased risky sexual behaviour. The country's government and civil society embarked on HIV awareness campaigns that are claimed to have played a central role in slowing down the epidemic since the mid-2000s. HIV-related mortality then fell by 70% between 2003 and 2013, which is attributed to high uptake of antiretroviral therapy (ART) and prevention of mother-to-child transmission (95%) prophylaxis. However, the epidemic has been characterised by a low paediatric ART coverage (35% in 2011 to 46.12% in 2013). Year 2014 saw an increase in adolescent and young adult HIV prevalence, which may be signalling a rebound of the epidemic. A more holistic approach which deals with the epidemic in its socio-political context is required to effectively lower the country's HIV burden.

Estimating the impact of universal antiretroviral therapy for HIV serodiscordant couples through home HIV testing: insights from mathematical models

INTRODUCTION

Antiretroviral therapy (ART) prevents HIV transmission within HIV serodiscordant couples (SDCs), but slow implementation and low uptake has limited its impact on population-level HIV incidence. Home HIV testing and counselling (HTC) campaigns could increase ART uptake among SDCs by incorporating couples' testing and ART referral. We estimated the reduction in adult HIV incidence achieved by incorporating universal ART for SDCs into home HTC campaigns in KwaZulu-Natal (KZN), South Africa, and southwestern (SW) Uganda.

METHODS

We constructed dynamic, stochastic, agent-based network models for each region. We compared adult HIV incidence after 10 years under three scenarios: (1) "Current Practice," (2) "Home HTC" with linkage to ART for eligible persons (CD4 <350) and (3) "ART for SDCs" regardless of CD4, delivered alongside home HTC.

RESULTS

ART for SDCs reduced HIV incidence by 38% versus Home HTC: from 1.12 (95% CI: 0.98-1.26) to 0.68 (0.54-0.82) cases per 100 person-years (py) in KZN, and from 0.56 (0.50-0.62) to 0.35 (0.30-0.39) cases per 100 py in SW Uganda. A quarter of incident HIV infections were averted over 10 years, and the proportion of virally suppressed HIV-positive persons increased approximately 15%.

CONCLUSIONS

Using home HTC to identify SDCs and deliver universal ART could avert substantially more new HIV infections than home HTC alone, with a smaller number needed to treat to prevent new HIV infections. Scale-up of home HTC will not diminish the effectiveness of targeting SDCs for treatment. Increasing rates of couples' testing, disclosure, and linkage to care is an efficient way to increase the impact of home HTC interventions on HIV incidence.

'We keep her status to ourselves': experiences of stigma and discrimination among HIV-discordant couples in South Africa, Tanzania and Ukraine

In HIV-discordant relationships, the HIV-negative partner also carries the burden of a stigmatised disease. For this reason, couples often hide their HIV-discordant status from family, friends and community members. This perpetuates the silence around HIV-discordant relationships and impacts on targeted HIV prevention, treatment and counselling efforts. This article reports on experiences of stigma and discrimination among HIV-discordant couples in South Africa, Tanzania and Ukraine. During 2008, HIV-discordant couples who had been in a relationship for at least one year were recruited purposively through health-care providers and civil society organisations in the three countries. Participants completed a brief self-administered questionnaire, while semi-structured interviews were conducted with each partner separately and with both partners together. Interviews were analysed using thematic content analysis. Fifty-one couples were recruited: 26 from South Africa, 10 from Tanzania, and 15 from Ukraine. Although most participants had disclosed their HIV status to someone other than their partner, few were living openly with HIV discordance. Experiences of stigma were common and included being subjected to gossip, rumours and name-calling, and HIV-negative partners being labelled as HIV-positive. Perpetrators of discrimination included family members and health workers. Stigma and discrimination present unique and complex challenges to couples in HIV sero-discordant relationships in these three diverse countries. Addressing stigmatisation of HIV-discordant couples requires a holistic human rights approach and specific programme efforts to address discrimination in the health system.

Advances in HIV prevention for serodiscordant couples

Serodiscordant couples play an important role in maintaining the global HIV epidemic. This review summarizes biobehavioral and biomedical HIV prevention options for serodiscordant couples focusing on advances in 2013 and 2014, including World Health Organization guidelines and best evidence for couples counseling, couple-based interventions, and the use of antiviral agents for prevention. In the past few years, marked advances have been made in HIV prevention for serodiscordant couples and numerous ongoing studies are continuously expanding HIV prevention tools, especially in the area of pre-exposure prophylaxis. Uptake and adherence to antiviral therapy remains a key challenge. Additional research is needed to develop evidence-based interventions for couples, and especially for male-male couples. Randomized trials have demonstrated the prevention benefits of antiretroviral-based approaches among serodiscordant couples; however, residual transmission observed in recognized serodiscordant couples represents an important and resolvable challenge in HIV prevention.

Seasonal PrEP for partners of migrant miners in southern Mozambique: a highly focused PrEP intervention

Introduction

To be used most effectively, pre-exposure prophylaxis (PrEP) should be prioritized to those at high risk of acquisition and would ideally be aligned with time periods of increased exposure. Identifying such time periods is not always straightforward, however. Gaza Province in southern Mozambique is characterized by high levels of HIV transmission and circular labour migration to mines in South Africa. A strong seasonal pattern in births is observable, reflecting an increase in conception in December. Given the potential for increased HIV transmission between miners returning in December and their partners in Gaza Province, PrEP use by the latter would be a useful means of HIV prevention, especially for couples who wish to conceive.

Methods

A mathematical model was used to represent population-level adult heterosexual HIV transmission in Gaza Province. Increased HIV acquisition among partners of miners in December, coinciding with the miners’ return from South Africa, is represented. In addition to a PrEP intervention, the scale-up of treatment and recent scale-up of male circumcision that have occurred in Gaza are represented.

Results

Providing time-limited PrEP to the partners of migrant miners, as opposed to providing PrEP all year, would improve the cost per infection averted by 7.5-fold. For the cost per infection averted to be below US$3000, at least 85% of PrEP users would need to be good adherers and PrEP would need to be cheaper than US$115 per person per year. Uncertainty regarding incidence of HIV transmission among partners of miners each year in December has a strong influence on estimates of cost per infection averted.

Conclusions

Providing time-limited PrEP to partners of migrant miners in Gaza Province during periods of increased exposure would be a novel strategy for providing PrEP. This strategy would allow for a better prioritized intervention, with the potential to improve the efficiency of a PrEP intervention considerably, as well as providing important reproductive health benefits.

Characterizing HIV epidemiology in stable couples in Cambodia, the Dominican Republic, Haiti, and India

Using a set of statistical methods and HIV mathematical models applied on nationally representative Demographic and Health Survey data, we characterized HIV serodiscordancy patterns and HIV transmission dynamics in stable couples (SCs) in four countries: Cambodia, the Dominican Republic, Haiti, and India. The majority of SCs affected by HIV were serodiscordant, and about a third of HIV-infected persons had uninfected partners. Overall, nearly two-thirds of HIV infections occurred in individuals in SCs, but only about half of these infections were due to transmissions within serodiscordant couples. The majority of HIV incidence in the population occurred through extra-partner encounters in SCs. There is similarity in HIV epidemiology in SCs between these countries and countries in sub-Saharan Africa, despite the difference in scale of epidemics. It appears that HIV epidemiology in SCs may share similar patterns globally, possibly because it is a natural ‘spillover’ effect of HIV dynamics in high-risk populations.

Dynamics of non-cohabiting sex partnering in sub-Saharan Africa: a modelling study with implications for HIV transmission

Objective

To develop an analytical understanding of non-cohabiting sex partnering in sub-Saharan Africa (SSA) using nationally representative sexual behaviour data.

Method

A non-homogenous Poisson stochastic process model was used to describe the dynamics of non-cohabiting sex. The model was applied to 25 countries in SSA and was fitted to Demographic and Health Survey data. The country-specific mean values and variances of the distributions of number of non-cohabiting partners were estimated.

Results

The model yielded overall robust fits to the empirical distributions stratified by marital status and sex. The median across all country-specific mean values was highest for unmarried men at 0.574 non-cohabiting partners over the last 12 months, followed by that of unmarried women at 0.337, married men at 0.192 and married women at 0.038. The median of variances was highest for unmarried men at 0.127, followed by married men at 0.057, unmarried women at 0.003 and married women at 0.000. The largest variability in mean values across countries was for unmarried men (0.103–1.206), and the largest variability in variances was among unmarried women (0.000–1.994).

Conclusions

Non-cohabiting sex appears to be a random ‘opportunistic’ phenomenon linked to situations that may facilitate it. The mean values and variances of number of partners in SSA show wide variation by country, marital status and sex. Unmarried individuals have larger mean values than their married counterparts, and men have larger mean values than women. Unmarried individuals appear to play a disproportionate role in driving heterogeneity in sexual networks and possibly epidemiology of sexually transmitted infections.

Phylogenetic studies of transmission dynamics in generalized HIV epidemics: an essential tool where the burden is greatest?

Efficient and effective HIV prevention measures for generalized epidemics in sub-Saharan Africa have not yet been validated at the population level. Design and impact evaluation of such measures requires fine-scale understanding of local HIV transmission dynamics. The novel tools of HIV phylogenetics and molecular epidemiology may elucidate these transmission dynamics. Such methods have been incorporated into studies of concentrated HIV epidemics to identify proximate and determinant traits associated with ongoing transmission. However, applying similar phylogenetic analyses to generalized epidemics, including the design and evaluation of prevention trials, presents additional challenges. Here we review the scope of these methods and present examples of their use in concentrated epidemics in the context of prevention. Next, we describe the current uses for phylogenetics in generalized epidemics and discuss their promise for elucidating transmission patterns and informing prevention trials. Finally, we review logistic and technical challenges inherent to large-scale molecular epidemiological studies of generalized epidemics and suggest potential solutions.

Indices to measure risk of HIV acquisition in Rakai, Uganda

Introduction

Targeting most-at-risk individuals with HIV preventive interventions is cost-effective. We developed gender-specific indices to measure risk of HIV among sexually active individuals in Rakai, Uganda.

Methods

We used multivariable Cox proportional hazards models to estimate time-to-HIV infection associated with candidate predictors. Reduced models were determined using backward selection procedures with Akaike's information criterion (AIC) as the stopping rule. Model discrimination was determined using Harrell's concordance index (c index). Model calibration was determined graphically. Nomograms were used to present the final prediction models.

Results

We used samples of 7,497 women and 5,783 men. 342 new infections occurred among females (incidence 1.11/100 person years,) and 225 among the males (incidence 1.00/100 person years). The final model for men included age, education, circumcision status, number of sexual partners, genital ulcer disease symptoms, alcohol use before sex, partner in high risk employment, community type, being unaware of a partner's HIV status and community HIV prevalence. The Model's optimism-corrected c index was 69.1 percent (95% CI = 0.66, 0.73). The final women's model included age, marital status, education, number of sex partners, new sex partner, alcohol consumption by self or partner before sex, concurrent sexual partners, being employed in a high-risk occupation, having genital ulcer disease symptoms, community HIV prevalence, and perceiving oneself or partner to be exposed to HIV. The models optimism-corrected c index was 0.67 (95% CI = 0.64, 0.70). Both models were well calibrated.

Conclusion

These indices were discriminative and well calibrated. This provides proof-of-concept that population-based HIV risk indices can be developed. Further research to validate these indices for other populations is needed.

Marital concurrency and HIV risk in 16 African countries

Research has identified sexual concurrency as a potential underlying driver of high HIV infection levels in sub-Saharan Africa, though few studies have explicitly examined the contribution of marital concurrency. Utilizing a multi-level model of Demographic and Health Surveys with HIV-biomarkers for sixteen African countries, this study assessed the relationship between an individual's HIV serostatus and rates of formal and informal marital concurrency (% polygamous unions, % extramarital partner past year) among married men and women. Mutually exclusive regional-level variables were constructed and modeled to test the contextual risk posed by living in a region with higher levels of formal and informal marital concurrency controlling for individual sexual partnerships and other covariates. Compared with regions where monogamous unions were more prevalent, the odds of having HIV were higher among individuals living in regions with more informal marital concurrency, but lower in regions with more polygamy, even accounting for individual-level sexual behavior. These results can help inform prevention policy and practice in sub-Saharan Africa.

Sources of HIV incidence among stable couples in sub-Saharan Africa

Introduction

The recent availability of efficacious prevention interventions among stable couples offers new opportunities for reducing HIV incidence in sub-Saharan Africa. Understanding the dynamics of HIV incidence among stable couples is critical to inform HIV prevention strategy across sub-Saharan Africa.

Methods

We quantified the sources of HIV incidence arising among stable couples in sub-Saharan Africa using a cohort-type mathematical model parameterized by nationally representative data. Uncertainty and sensitivity analyses were incorporated.

Results

HIV incidence arising among stable concordant HIV-negative couples contribute each year, on average, 29.4% of total HIV incidence; of those, 22.5% (range: 11.1%–39.8%) are infections acquired by one of the partners from sources external to the couple, less than 1% are infections acquired by both partners from external sources within a year and 6.8% (range: 3.6%–11.6%) are transmissions to the uninfected partner in the couple in less than a year after the other partner acquired the infection from an external source. The mean contribution of stable HIV sero-discordant couples to total HIV incidence is 30.4%, with most of those, 29.7% (range: 9.1%–47.9%), being due to HIV transmissions from the infected to the uninfected partner within the couple. The remaining incidence, 40.2% (range: 23.7%–64.6%), occurs among persons not in stable couples.

Conclusions

Close to two-thirds of total HIV incidence in sub-Saharan Africa occur among stable couples; however, only half of this incidence is attributed to HIV transmissions from the infected to the uninfected partner in the couple. The remaining incidence is acquired through extra-partner sex. Substantial reductions in HIV incidence can be achieved only through a prevention approach that targets all modes of HIV exposure among stable couples and among individuals not in stable couples.

The risk of HIV transmission within HIV-1 sero-discordant couples appears to vary across sub-Saharan Africa

BACKGROUND

Representative and precise estimates for the annual risk of HIV transmission (ϕ) from the infected to the uninfected partner in a stable HIV-1 sero-discordant couple (SDC) are not available. Nevertheless, quantifying HIV infectiousness is critical to understanding HIV epidemiology and implementing prevention programs.

MATERIALS AND METHODS

We estimated ϕ and examined its variation across 23 countries in sub-Saharan Africa (SSA) by constructing and analyzing a mathematical model that describes HIV dynamics among SDCs. The model was parameterized using empirical measures such as those of the nationally representative Demographic and Health Surveys. Uncertainty and sensitivity analyses were conducted to assess the robustness of the findings.

RESULTS

We estimated a median ϕ of 11.1 per 100 person-years across SSA. A clustering based on HIV population prevalence was observed with a median ϕ of 7.5 per 100 person-years in low HIV prevalence countries (<5%) compared to 19.5 per 100 person-years in high prevalence countries (>5%). The association with HIV prevalence explained 67% of the variation in ϕ, and suggested an increase of 0.95 per 100 person-years in ϕ for every 1% increase in HIV prevalence.

CONCLUSIONS

Empirical measures from cohort studies appear to underestimate HIV infectiousness in SSA. The risk of HIV transmission among SDCs appears also to vary across SSA, and this may have contributed to the contrasting HIV epidemic trajectories in this continent.

Effect of early antiretroviral therapy on sexual behaviors and HIV-1 transmission risk among adults with diverse heterosexual partnership statuses in Côte d'Ivoire

Background. The effect of early initiation of antiretroviral therapy (ART; ie, at CD4⁺ T-cell counts >350 cells/mm³) on sexual behaviors and human immunodeficiency virus type 1 (HIV) transmission risk has not been documented in populations other than HIV-serodiscordant couples in stable relationships.

Methods. On the basis of data from a behavioral study nested in a randomized, controlled trial (Temprano-ANRS12136) of early ART, we compared proportions of risky sex (ie, unprotected sex with a partner of negative/unknown HIV status) reported 12 months after inclusion between participants randomly assigned to initiate ART immediately (hereafter, “early ART”) or according to ongoing World Health Organization criteria. Group-specific HIV transmission rates were estimated on the basis of sexual behaviors and viral load–specific per-act HIV transmission probabilities. The ratio of transmission rates was computed to estimate the protective effect of early ART.

Results. Among 957 participants (baseline median CD4⁺ T-cell count, 478 cells/mm³), 46.0% reported sexual activity in the past month; of these 46.0%, sexual activity for 41.5% involved noncohabiting partners. The proportion of subjects who engaged in risky sex was 10.0% in the early ART group, compared with 12.8% in the standard ART group (P = .17). After accounting for sexual behaviors and viral load, we estimated that the protective effect of early ART was 90% (95% confidence interval, 81%–95%).

Conclusion. Twelve months after inclusion, patients in the early and standard ART groups reported similar sexual behaviors. Early ART decreased the estimated risk of HIV transmission by 90%, suggesting a major prevention benefit among seronegative sex partners in stable or casual relationships with seropositive individuals.

Incident HSV-2 infections are common among HIV-1-discordant couples

BACKGROUND

The synergy between herpes simplex virus type 2 (HSV-2) and human immunodeficiency virus type 1 (HIV-1) is well known, but lack of knowledge about the epidemiology of HSV-2 acquisition in HIV-1-discordant couples hampers development of HSV-2 prevention interventions that could reduce HIV-1 transmission.

METHODS

HIV-1-discordant couples were enrolled in Nairobi, Kenya, and followed for up to 2 years. HSV-2 status was determined using HerpeSelect HSV-2 ELISA. Correlates of prevalence and incidence were assessed. RESULTS.: Of 469 HIV-1-discordant couples, at baseline, 353 (75.3%) were affected by HSV-2, of which 189 (53.5%) were concordantly HSV-2 seropositive and 164 (46.5%) were HSV-2-discordant. Prevalence was lowest among HIV-1-uninfected men (39.9%) compared to HIV-1-infected women (64.8%), HIV-1-infected men (66.7%), and HIV-1-uninfected women (68.5%). During follow-up, HSV-2 seroincidence was 14.9 per 100 person-years. Incidence was 1.6-fold higher among females compared to males (95% confidence interval [CI], 1.00-2.48) and 2.5-fold higher in HIV-1-infected compared to uninfected women (95% CI, 1.12-5.74). At least 30% of incident HSV-2 infections originated from an outside partner.

CONCLUSIONS

The high HSV-2 prevalence and incidence in HIV-1-discordant couples in sub-Saharan Africa suggest HSV-2 treatment and prevention could be an effective targeted strategy to reduce HSV-2 and HIV-1 transmission in this high-risk population.

Integrated strategies for combination HIV prevention: principles and examples for men who have sex with men in the Americas and heterosexual African populations

Combination HIV prevention is of high priority for increasing the impact of partially efficacious HIV prevention interventions for specific populations and settings. Developing the package requires critical review of local epidemiology of HIV infection regarding most-impacted populations and those at high risk of HIV transmission and acquisition, drivers of HIV infection, and available interventions to address these risk factors. Interventions should be considered in terms of the evidence basis for efficacy, potential synergies, and feasibility of delivery at scale, which is important to achieve high coverage and impact, coupled with high acceptability to populations, which will impact uptake, adherence, and retention. Evaluation requires process measures of uptake, adherence, retention, and outcome measures of reduction in HIV infectiousness and acquisition. Three examples of combination prevention concepts are summarized for men who have sex with men in the Americas, young women in sub-Saharan Africa, and HIV serodiscordant couples.

HIV-1 transmission within marriage in rural Uganda: a longitudinal study

Background

Early initiation of antiretroviral therapy reduces risk of transmission to the uninfected partner in HIV discordant couples, but there are relatively little observational data on HIV transmission within couples from non-trial settings. The aims of this paper are to estimate HIV incidence among HIV discordant couples using longstanding observational data from a rural Ugandan population and to identify factors associated with HIV transmission within couples, including the role of HSV-2 infection.

Methods

Using existing data collected at population-wide annual serological and behavioural surveys in a rural district in southwest Uganda between 1989 and 2007, HIV discordant partners were identified. Stored serum samples were tested for HSV-2 serostatus using the Kalon ELISA test. HIV seroconversion rates and factors association with HIV seroconversion were analysed using Poisson regression.

Results

HIV status of both partners was known in 2465 couples and of these 259 (10.5%) were HIV serodiscordant. At enrolment, HSV-2 prevalence was 87.3% in HIV positive partners and 71.5% in HIV negative partners. Of the 259 discordant couples, 62 converted to HIV (seroconversion rate 7.11/100 PYAR, 95%CI; 5.54, 9.11) with the rate decreasing from 10.89 in 1990–1994 to 4.32 in 2005–2007. Factors independently associated with HIV seroconversion were female sex, non-Muslim religion, greater age difference (man older than woman by more than 15 years), higher viral load in the positive partner and earlier calendar period. HSV-2 was not independently associated with HIV acquisition (HR 1.62, 95%CI; 0.57, 4.55) or transmission (HR 0.61, 95%CI; 0.24, 1.57). No transmissions occurred in the 29 couples where the index partner was on ART during follow up (872 person-years on ART).

Discussion

HIV negative partners in serodiscordant couples have a high incidence of HIV if the index partner is not on antiretroviral therapy and should be provided with interventions such as couple counselling, condoms and antiretroviral treatment.